Global Warming and Climate Change

Global Warming

Global warming refers to a slow and steady rise in the temperature of the earth’s surface, atmosphere, seas and oceans.  Global warming has been observed since the mid 20th century.  The increase in the earth’s surface and atmospheric temperature affects the environment and causes climatic changes.  Global warming may have many causes, but it is mostly associated with the release of excessive amounts of greenhouse gases in the atmosphere.

     Global warming occurs when Carbon dioxide (CO2) and other air pollutants absorb sunlight and solar radiation that have bounced from the earth’s surface.  Normally this radiation would escape into space, but these pollutants trap the heat and cause the earth to get hotter.  These heat trapping pollutants mainly Carbon dioxide, Methane, Nitrous oxide and synthetic fluorinated gases are known as greenhouse gases, and getting the planet hotter is called the Greenhouse effect.  Global warming is directly attributed to the huge efforts to achieve rapid economic growth which involves indiscriminate use of energy sources in the industrial and other economic sectors. These industries result in massive release of toxins, gases and pollutants that heat up the atmosphere.  Thus, global warming can be seen as a direct consequence of development policies and programmes that have not only ignored environmental issues, but also lost sight of the interest of the future generation.

Greenhouse Gases

         Carbon dioxide, Methane, water vapour, Nitrous oxide etc.. are called greenhouse gases.  These gases act as a greenhouse around the earth.  These gases allow the heat from the sun to enter into earth’s atmosphere, but do not allow it to escape back into space. Thus, the more greenhouse gases there are, the larger the heat is trapped inside the earth’s atmosphere.  The greenhouse gases keep the earth’s surface warm, and the habitat of human, animal, vegetation and marine life becomes warmer.

         In the absence of greenhouse gases no heat would have been trapped in the atmosphere and the earth would have been extremely cold and lifeless.  But naturally occurring greenhouse gases in their naturally occurring amounts are good for the earth and life, with excessive amounts of greenhouse gases, the earth’s atmosphere warms up unnaturally.  This leads to melting of glaciers, and increase in sea levels, warming of oceans, increased and untimely rainfall, damage to marine life etc.

         Over the decades of the 20th century, due to increase of industrialization and economic development, large scale burning of fossil fuels or petroleum products for meeting growing energy requirements, rapid population growth and growing income and consumption levels have been the main contributors to increased emissions of greenhouse gases. In the future the emissions at their current rate are likely to induce changes in the climate system larger than those observed in the 20th century.

          Global climate change, due to rising levels of Greenhouse gases and depletion of the Ozone layer in the atmosphere, is one of the serious environmental concerns of the world.  The water cycle is totally dependent on the temperature of the earth.  Increasing global temperature damages the water cycle, causing floods and droughts, groundwater recharge also affected.  Through the 20th century the average rate of global sea level has been rising.  Changing environmental conditions affect animal life.  Crop yield is decreasing due excessive heat and droughts.  Changes in the severity and frequency of extreme heat and cold, floods and droughts, coupled with local air pollution and allergens may result in changes in infectious disease occurrence in local food production and also cause undernutrition, leading to impaired child development.

    Now it's time for all the countries to come together and start the activities that reduce greenhouse gas emission and enhance the capacity of carbon sinks to absorb the greenhouse gases from the atmosphere.  Many countries, both the developed and developing, are aiming for cleaner, less polluting technologies. Use of these technologies could result in substantial reduction in carbon dioxide and other greenhouse gases.